This invention relates to scintillators and more particularly it relates to inorganic scintillation crystals of the type characterized as alkali metal halides and inorganic oxides. These crystals are noted for their ability to scintillate or emit pulses of light when exposed to ionizing radiation. When the crystals are optically coupled to a suitable detector, the scintillation events or pulses can be be detected, measured and analyzed for the purpose of characterizing the amount or nature of the radiation energy to which the crystal is exposed.
Some desirable characteristics of inorganic halide and oxide scintillators are their high density for gamma ray stopping power, large pulse height or light output for detection for low energy interactions, and short decay time for rapid counting of scintillation events.
Pulses of light emitted during scintillation are detected by a device such as a photomultiplier tube (PMT) or a silicon photodiode. The effectiveness of the detector in seeing the light flashes within a crystal is dependent upon the number of flashes impinging on the detector. On the other hand, the flashes within the crystal move in random directions and may pass out of the crystal without being detected.